Refrigeration



Dec. 27, 1938. c SHAGALQFF I $141,882

" REFRIGERATION Filed Oct. 2O, 1936 INVENTOR.

MM (1- WW ifl w ATTORNEY.

Patented Dec. 27, 1938 UNITED STATES REFRIGERATION Harry 0. Shagalofi,Evansville, Ind., assignor to Serve], Inc., New York, N. Y., acorporation of Delaware Application October 20, 1936, Serial No. 106,501

5 Claims.

My invention relates to refrigeration, and more particularly to controlof refrigeration apparatus adapted to be heated by a liquid fuel burner.

It is an object of my invention to provide an improved control forrefrigeration apparatus adapted to be heated by a liquid fuel burnerwherein the flow of liquid fuel to the burner is effectively controlledto regulate the quantity of heat applied to the refrigeration apparatus.

Another object of my invention is to provide an improved control forrefrigeration apparatus heated by a liquid fuel burner in which theburner is operated continuously and effective to maintain an enclosedspacev at a substantially constant temperature.

Further objects and advantages of my invention will become apparent fromthe following de.- scription and accompanying drawing forming a part ofthis specification, and of which Fig. 1 is a diagrammatic illustrationof refrigeration apparatus and a liquid fuel burner provided with acontrol device embodying my invention; and Fig. 2 is an enlargedsectional view taken on line 22 of Fig. 1 to illustrate the controldevice more clearly.

Referring to Fig. 1 of the drawing, I have shown my invention applied torefrigeration apparatus of a uniform pressure absorption type, generallyas described in Patent No. 1,609,334

to B. C. von Platen and C. G. Munters, in which an auxiliary pressureequalizing gas is employed. The refrigeration apparatus comprises agenerator 10 having a rear chamber H and a forward chamber I2communicating with an upward ex-' tending standpipe or separator M. Thegenerator l contains a body of absorption liquid having a suitablerefrigerant in solution therein,

and, although I do not wish to be limited thereto, the absorption liquidand refrigerant may be water and ammonia, respectively.

The generator I0 is heated by a liquid fuel burner l5 which projects itsflame into the downwardly extending forward end of a horizontal flue l6which extends through the generator, A suitable liquid fuel, such askerosene, is delivered from a supply vessel ll to the burner 15, as willbe described hereinafter.

The heat applied to thegenerator causes ammonia vapor and absorptionliquid in chamber l l to pass through an opening (not shown) in thelower end of a small vertical conduit l8 which constitutes a vapor-liftand conducts ammonia vapor and absorption liquid to the upper end of thestand-pipe l4. Liberated ammonia vapor entering the stand-pipe Hi fromconduit l8, as well as the ammonia vapor expelled from solution in thestandpipe l4 and chamber I2, flows through a conduit l9 which extendsdownward within an analyzer 20. The ammonia vapor passes upward throughabsorption liquid in the analyzer 20 and is arranged within a storagecompartment 26 having thermally insulated walls 21.

An inert gas, such as hydrogen, enters the lower part of the coolingelement 25 from an outer passage of a gas heat exchanger 28. Thehydrogen and liquid ammonia are in counterfiow, and the ammoniaevaporates and diffuses into the hydrogen with consequent absorption ofheat from the surroundings of the cooling ele- .ment. The resultingmixture of ammonia and hydrogen, that is, gas rich in ammonia, fiowsdownward from the cooling element through a conduit 29 forming the inner'passage'of the gas heat exchanger 28. Thelower end of the conduit 29communicates with the lower end of an absorber 30 about which isarranged a coil 3| through which a suitable cooling medium iscirculated.

Ammonia is absorbed out of the rich gas mixture into weak absorptionliquid which enters the upper part of the absorber 30 through avertically extending conduit 32. The hydrogen, which is practicallyinsoluble and weak in ammonia, passes upward from the absorber 30through conduit 33 and the outer passage ,of the gas heat exchanger 28and into the cooling element 25. The gas heat exchanger 28 effectivelytransfers heat from the weak gas flowing toward the cooling element tothe rich gas flowing to the absorber 30.

The absorption liquid flowing downward through the absorber 30 incounter-flow to the gas mixture becomes enriched in ammonia and passesthrough conduit 34, the outer passage of a liquid heat exchanger 35 andconduit 36 into the lower part of the analyzer 20. From the analyzer 211the enriched absorption liquid flows through conduit 31 into chamber llof the generator Ill.

. Liberated ammonia vapor and absorption liquid.

pass upward through the vertical conduit l8 into the upper part of thestandpipe M, as explained above, to a higher level than it is in the'absorber 30, and absorption liquid weak in ammonia flows from thechamber l2 through conduit 38,

' inner passage of the-liquid heat exchanger 35,

and conduit 32 into the upper end of the absorber 30. A portion of theconduit 32 is provided with a plurality of fins 39 to effect additionalcooling of the weak absorption liquid entering the absorber 30. V a

In order to vary the total pressure in the refrigeration system justdescribed with changes in air temperature, a vessel 40 for storinghydrogen is provided having one part thereof connected by a conduit 4|to the lower end of the condenser 22, and another part thereof connectedby a conduit 42 to the gas circuit. The vessel 40 and conduits 4| and 42provide a path of flow from the condenser 22 to the gas circuit, so thatany hydrogen which passes through the condenser can flow to the gascircuit and not be trapped in the condenser. Further, should the airtemperature increase so that ammonia is not liquefied in the condenser,the ammonia. vapor will flow through conduit 4| to displace hydrogen inthe vessel 49 and force hydrogen through conduit 42 into the gascircuit, thereby raising the total pressure in the system so that anadequate condensing pressure results for the increased air temperature.

The burner l5 comprises two perforated cylinders 43 and 44 arrangedconcentrically one within the other above a burner well 45 to provide acombustion chamber 46. The top of the inner cylinder 43 is provided witha closure member 41, as shown in Fig. 1, and about the cylinder 44 isarranged a frusto-conical shell 48. When the burner is being operated,air is drawn upward through the inner cylinder 43 and the space betweenthe outer cylinder 44 and the shell 43 and mixes with vaporized fuel toprovide a combustible mixture.

In accordance with my invention, in order to controlthe quantity of heatapplied to the refrigeration apparatus, the annular burner well 45 is soconstructed that a depression 49 is provided which extends only about. apart of the circumference of the burner well. The portion 49, therefore,is of greater depth and extends below the remaining part of the burnerwell 45. To the portion 49 of the burner well is connectedthe upper endof a vertical conduit 50, the lower end of which is connected to anintermediate portion of a horizontal conduit 5| having the ends thereofconnected to the lower parts of vessels 52 and 53 which are formedintegrally with a casing 54. The casing 54 forms a chamber 55 into whichliquid fuel is conducted througha conduit 55 from the supply vesselLiquid fuel is adapted to flow by gravity from the supply vessel IT tothe chamber 55, and the conduit 56 is provided with a manually operablevalve 51 for shutting off the supply of fuel to the burner when thelatter is not being operated.

The flow of liquid fuel into the vessels 52 and 53 is controlled byvalves 53 and 59 which are disposed at inlet openings at the bottoms ofthe vessels and connected by light rods 50 and 6| to floats 52-. and 53.The vessels 52 and 53 are provided with removable covers 54 and 65,respec-' tively. When liquid fuel in either one of the vessels 52 and 53falls below a predetermined level, the float therein is lowered wherebythe valve associated therewith is caused to open and admit liquid fuelinto the vessel to bring the liquid fuel therein to the predeterminedlevel. The control valves 53 and 59, therefore, function to maintain aconstant level of liquid fuel in the vessels 52 and 53. Liquid fuelflows from the vessels 52 and 53 through horizontal conduit 5| andvertical conduit 59 into the annular burner well 45.

In the horizontal conduit 5| is connected a control valve 66 forcontrolling the flow of liquid fuel from the vessel 53 to the burnerwell 45. The control valve 65 comprises a casing having a partition 61provided with an opening which is adapted to be closed by a valve 63.The valve 63 is connected by a rod 69 to an expansible bellows 10arranged within the casing. The bellows I is connected by a tube H to athermal bulb or element 12 which is secured to and in thermal contactwith the cooling element 25 of the refrigeration apparatus. Theexpansible bellows l0, tube II, and bulb l2 constitute an expansiblefluid thermostat adapted to maintain the storage compartment 25 at asubstantiallyconstant temperature, and contain a volatile fluid whichincreases and decreases in volume with corresponding changes intemperature.

When the cooling element 25 tends to rise above a desired temperature,the expansible fluid thermostat causes the expansible bellows 10 toexpand and move the valve 68 to its open position against the tension ofspring 13 and thus permit the flow of liquid fuel from the vessel 53 tothe burner well 45; and conversely, when the cooling element 25 tends tofall below the desired temperature, the expansible fluid thermostatcauses the expansible bellows 10 to contract and permit the valve 68 tobe urged toward its closed position by the spring'l3 to shut oil theflow of liquid fuel from the vessel 53 to the burner well 45.

The control valve 58, rod 50, and float 62 are so constructed that thepredetermined level of liquid fuel maintained in the vessel 52 isslightly below that maintained in the vessel 53 by the valve 59, rod 6|,and float 63. When the burner I-is not being operated, the coolingelement 25 is above the desired temperature and .the valve 68 is in itsopen position whereby liquid'fuel is permitted to flowv from the vessel53 to the burner well 45. Under these conditions, the level of liquidfuel in the vertical conduit 50 and burner well 45 is at the same levelas the liquid fuel in the vessel 53. This level, which is indicated atA,is such that, when the burner I5 is lighted, the flame produced by theburner will apply heat to the refrigeration apparatus at a ratesuflicient to heat refrigerant to its vaporization temperature orboiling point so that refrigerant is vaporized and expelled outofsolution from the absorption liquid. With the burner flame of such sizethat refrigerant is expelled out of solution from absorption liquid, therefrigerant apparatus operates in the manner described above to producecold in the storage compartment 26.

When the cooling element 25 tends to fall below the desired temperature,the expansible fluid thermostat, as explained above, becomes operativeto close the valve 68 whereby liquid fuel no longer flows from thevessel 53 to the burner well 45 and liquid fuel only flows to the burnerwell from the vessel 52. The level of liquid fuel maintained in thevessel 52 is slightly below that maintained in the vessel 53, asindicated at B, and is such that, when the burner I5 is not beingoperated and the valve 58 is closed, liquid fuel only flows into thedepressed portion 49 of the burner well 45. The level of liquid fuel inthe depressed portion 49 of the burner well 45 is such that, with thevalve 68 closed and the burner l5 lighted, theflame produced by theburner will apply heat to the refrigeration apparatus at such a ratethat only heat of liquid is supplied to the refrigerant and therefrigerant is heated to a temperature slightly below its vaporizationtemperature. Since refrigerant is not expelled out of absorption liquidunder these conditions, cold is not produced in the storage compartment25 I6 ture, the level of liquid fuel in the vessel 53 determines thenormal rate at which fuel is supplied to the burner l; and that when thecooling element 25 tends to fall below the desired temperature, thelevel of liquid fuel in the vessel 52 determines the modified rate atwhich fuel .is supplied to the burner l5.

By controlling the flow of liquid fuel in the manner described above,the burner I5 may be operated continuously to maintain the enclosedspace 26 at a substantially constant temperature. Further, suitablemeans may be'readily provided to maintain the burnerat a reduced orminimum flame rather than a maximum flame to permit defrosting of thecooling element 25 without any necessity of shutting off the burner l5.This is a distinct advantage because the generator l0 and its contentswould be cooled by the surroundings if no heat were applied to thegenerator during a defrosting period. Subsequently, when the coolingelement 25 has been defrosted, heat would have to be applied to thegenerator i0 and its contents fora relatively long period of time beforerefrigerant is heated to its vaporization temperature and expelled outof solution from the absorption liquid. By providing a control forliquid fuel whereby the application of heat to the generator is notdiscontinued but ismodified to apply heat to the generator at such arate that the refrigerant is heated to a temperature slightly below itsvaporization temperature, the refrigerant is heated to its vaporizationtemperature in a relatively short time after the termination of thedefrosting period, so that the cooling element 25 is effectivesubstantially immediately to maintain the storage compartment 26 at thedesired temperature.

Although I have described and illustrated a particular embodiment of myinvention, it will be apparent to those skilled in the art thatmodifications may be made without departing from the spirit and scope ofthe invention, as pointed out in the following claims.

What is claimed is:

1. The combination with a refrigeration system having a generatoradapted to be heated, a condenser, an absorber, an evaporator, and interconnecting conduits forming. a closed system for circulation offluids, expulsion of refrigerant and evaporation of refrigerant toproduce refrigeration, said system being so constructed and charged thatthe quantity of refrigeration produced is a function of the quantity ofheat supplied to the generator; of a liquid fuel combustion device forheating said generator by vaporization of fuel oil to supply heat to thegenerator in proportion to the level of oil in the combustion device,and apparatus for feeding oil to said combustion device including aplurality of constant level devices each adapted to maintain a differentliquid level in said combustion device, and means for connecting anddisconnecting at least one of said constant level devices with respectto said combustion device responsive to a temperature conditionaffectedby said refrigeration system.

2. The combination as set forth in claim 1 in which said constant leveldevices include float operated valves, and said means is a thermostaticvalve.

3. The combination with a refrigeration system having a generatoradapted to be heated, a

condenser, an absorber an evaporator, and interconnecting conduitsforming a closed system for circulation'of fluids, expulsion ofrefrigerant and evaporation of refrigerant to produce refrigeration,said system being so constructed and charged that the quantity ofrefrigeration produced is a function of the quantity. of heat suppliedto the generator; of a liquid fuel combustion device for heating saidgenerator by vaporization of fuel oil to supply heat to the generator inproportion to the level of oil in the combustion device, and apparatusfor feeding oil to said combustion device including a supply conduit, atleast two chambers connected to receive fuel oil from said conduit, afloat operated valve for controlling flow of liquid fuel into each ofsaid chambers to maintain substantially constant but different levels ofliquid fuel in the chambers, conduits for conducting liquid fuel fromsaid chambers to said combustion device, and a thermostatic valve forcontrolling flow of liquid fuel to said combustion device from thechamber in which the highest liquid level is maintained responsive to atemperature condition affected by said evaporator.

4. The combination with a refrigeration system having a generatoradapted to be heated, a condenser, an absorber, an evaporator, andinterconnecting conduits forming a closed system for circulation offluids, expulsion of refrigerant and evaporation of refrigerant toproduce refrigeration, said system being so constructed and charged thatthe quantity of refrigeration produced is a function of the quantity ofheat supplied to the generator; of a liquid fuel burner'for heating saidgenerator by vaporization of liquid fuel to supply heat to the generatorin proportion to the level of liquid fuel in the burner, apparams forfeeding liquid fuel to said burner including a plurality of conduitsconnected to said burner, a device in each of said conduits to controlflow of liquid fuel therethrough responsive to liquid level, and meansfor controlling flow of liquid through at least one of said conduitsresponsive to a temperature condition affected by said refrigerationsystem.

5. In a method of refrigeration which includes circulation of fluids,expulsion of refrigerant and evaporation of refrigerant to producerefrigeration in accordance with a quantity of energy supplying heat;that improvement which consists in producing the energy supplying heatby vaporization and combustion of liquid fuel at a rate proportional tothe level of liquid fuel in a place of vaporization, supplying liquidfuel to said place of vaporization from a plurality of places ofaccumulation, conducting liquid fuel to said several places ofaccumulation at rates each responsive to a different liquid level insaid places respectively, and controlling flow of liquid fuel from atleast one of said places to said place of vaporization responsive to atemperature condition affected by the refrigeration produced.

HARRY r1. SHAGALOFF.

